Diamondoids are cage-shaped hydrocarbon molecules possessing rigid structures which are tiny fragments of a diamond crystal lattice. Adamantane is the smallest member of the diamondoid series and consists of a single cage structure of the diamond crystal lattice. Diamantane contains two adamantane subunits face-fused to each other, triamantane three, tetramantane four, and so on. While there is only one isomeric form of adamantane, diamantane and triamantane, there are four different isomeric tetramantanes (i.e., four different shapes containing four adamantane subunits). Two of the isomeric tetramantanes are enantiomeric. The number of possible isomers increases rapidly with each higher member of the diamondoid series.
Adamantane, which is commercially available, has been functionalized. For instance, U.S. Pat. No. 3,832,332 describes a polyamide polymer formed from alkyladamantane diamine; U.S. Pat. No. 5,017,734 discusses the formation of thermally stable resins from ethynyl adamantane derivatives; and, U.S. Pat. No. 6,235,851 reports the synthesis and polymerization of a variety of adamantane derivatives.
The following references related to adamantane and derivatives formed from adamantane:    Capaldi, et al., Alkenyl Adamantanes, U.S. Pat. No. 3,457,318, issued Jul. 22, 1969    Thompson, Polyamide Polymer of Diamino Methyl Adamantane and Dicarboxylic Acid, U.S. Pat. No. 3,832,332, issued Aug. 27, 1974    Baum, et al., Ethynyl Adamantane Derivatives and Methods of Polymerization Thereof, U.S. Pat. No. 5,017,734, issued May 21, 1991    Ishii, et al., Polymerizable Adamantane Derivatives and Process for Producing Same, U.S. Pat. No. 6,235,851, issued May 22, 2001    McKervey, et al., Synthetic Approaches to Large Diamondoid Hydrocarbons, Tetrahedron 36, 971-992 (1980)    Lin, et al., Natural Occurrence of Tetramantane (C22H28), Pentamantane (C26H32) and Hexamantane (C30H36) in a Deep Petroleum Reservoir, Fuel 74:10, 1512-1521 (1995)    Chen, et al., Isolation of High Purity Diamondoid Fractions and Components, U.S. Pat. No. 5,414,189, issued May 9, 1995    Balaban et al., Systematic Classification and Nomenclature of Diamond Hydrocarbons-I, Tetrahedron 34, 3599-3606 (1978)    Gerzon et al., The Adamantyl Group in Medicinal Agents, 1. Hypoglycemic N-Arylsulfonyl-N-adamantylureas, Journal of Medicinal Chemistry 6 (6), 760-763 (November 1963)    Marshall et al., Further Studies on N-Arylsulfonyl-N-alkylureas, Journal of Medicinal Chemistry 6, 60-63 (January 1963)    Marshall et al., N-Arylsulfonyl-N-alkylureas, Journal of Organic Chemistry 23, 927-929 (June 1958)    Reinhardt, Biadamantane and Some of its Derivatives, Journal of Organic Chemistry 27, 3258-3261, (September 1962)    Sasaki et al., Synthesis of Adamantane Derivatives. II. Preparation of Some Derivatives from Adamantylacetic Acid, Bulletin of the Chemical Society of Japan 41:1, 238-240 (June 1968)    Stetter et al, Ein Beitrag zur Frage der Reaktivitat von Bruckenkopf-Carboniumionen, Uber Verbindungen mit Urotropin-Struktur, XXVI, Chem. Ber. 96 550-555, (1963)    Hass et al, Adamantyloxycarbonyl, a New Blocking Group. Preparation of 1-Adamantyl Chloroformate, Journal of the American Chemical Society 88:9, 1988-1992 (May 5, 1966)    Stetter et al, Neue Moglichkeiten der Direktsubstitution am Adamantan, Uber Verbindungen mit Urotropin-Struktur, XLIII, Chem. Ber. 102 (10), 3357-3363 (1969)    von H. U. Daeniker, 206. 1-Hydrazinoadamantan, Helvetica Chimica Acta 50, 2008-2010 (1967)    Stetter et al, Uber Adamantan-phosphonsaure-(1)-dichlorid, Uber Verbindungen mit Urotropin-Struktur, XLIV, Chem. Ber. 102 (10), 3364-3366 (1969)    Lansbury et al, Some Reactions of ∀-Metalated Ethers, The Journal of Organic Chemistry 27:6, 1933-1939 (Jun. 12, 1962)    Stetter et al, Herstellung von Derivaten des 1-Phenyl-adamantans, Uber Verbindungen mit Urotropin-Struktur, XXXI, Chem. Ber. 97 (12), 3488-3492 (1964)    Nordlander et al, Solvolysis of 1-Adamantylcarbinyl and 3-Homoadamantyl Derivatives. Mechanism of the Neopentyl Cation Rearrangement, Journal of the American Chemical Society 88:19 (Oct. 5, 1966)    Sasaki et al, Substitution Reaction of 1-Bromoadamantane in Dimethyl Sulfoxide: Simple Synthesis of 1-Azidoadamantane, Journal of the American Chemical Society 92:24 (Dec. 2, 1970)    Chakrabarti et al, Chemistry of Adamantane. Part II. Synthesis of 1-Adamantyloxyalkylamines, Tetrahedron Letters 60, 6249-6252 (1968)    Stetter et al, Derivate des 1-Amino-adamantans, Uber Verbindungen mit Urotropin-Struktur, XXIV, Chem. Ber. 95, 2302-2304 (1962)    Stetter et al, Zur Kenntnis der Adamantan-carbonsaure, Uber Verbindungen mit Urotropin-Struktur, XVII, Chem. Ber. 93, 1161-1166 (1960)    Makarova et al, Psychotropic Activity of Some Aminoketones Belonging to the Adamantane Group, Pharmaceutical Chemistry Journal, 34:6 (2000)
As noted above, heterodiamondoids are those diamondoids in which at least one cage carbon atom is replaced by a heteroatom. The following references describe more details about heteroadamantanes and heterodiamantanes.    Meeuwissen et al, Synthesis of 1-Phosphaadamantane, Tetrahedron Letters, 39:24, 4225-4228 (1983)    Boudjouk et al, The Reaction of Magnesium with cis-1,3,5-Trsi(bromomethyl)cyclohexane. Evidence For a Soluble Tri-grignard, Journal of Organometallic Chemistry 281, C21-C23 (1985)    Boudjouk et al, Synthesis and Reactivity of 1-Silaadamantyl Systems, Journal of Organometallic Chemistry 2, 336-343 (1983).    Krishnamurthy et al, Heteroadamantanes. 2. Synthesis of 3-Heterodiamantanes, Journal of Organometallic Chemistry, 46:7, 1389-1390 (1981)    Udding et al, A Ring-opening Reaction of and Some Cyclisations to the Adamantane System. A Quasi-favorsky Reaction of a ∃-bromoketone, Tetrahedron Letters 55, 5719-5722 (1968)    Blaney et al, Chemistry of Diamantane, Part II. Synthesis of 3,5-disubstituted Derivatives, Synthetic Communications 3:6, 435-439 (1973)    Henkel et al, Neighboring Group Effects in the ∃-halo Amines. Synthesis and Solvolytic Reactivity of the anti-4-Substituted 2-Azaadamantyl System, Journal of Organometallic Chemistry 46, 4953-4959 (1981)    Becker et al, A Short Synthese of 1-azaadamantan-4-one and the 4r and 4s Isomers of 4-Amino-1-azaadamantane, Synthesis, (11), 1080-1082 (1992)    Eguchi et al, A Novel Route to the 2-Aza-adamantyl System via Photochemical Ring Contraction of Epoxy 4-Azahomoadamantanes, Journal of Organometallic Chemistry, Commun., 1147-1148 (1984)    Gagneux et al, 1-Substituted 2-Heteroadamantanes, Tetrahedron Letters 17, 1365-1368 (1969)    Bubnov et al, A Novel Method of Synthesis of 1-azaadamantane from 1-boraadamantane, Journal of Organometallic Chemistry 412, 1-8 (1991).    Sasaki et al, Synthesis of Adamantane Derivatives. 39. Synthesis and Acidolysis of 2-Azidoadamantanes. A Facile Route to 4-Azahomoadamant-4-enes, Heterocycles 7:1 315-320 (1977)    Sasaki et al, Synthesis of Adamantane Derivatives. 47. Photochemical Synthesis of 4-Azahomoadamant-4-enes and Further Studies on Their Reactivity in Some Cycloadditions, Journal of Organometallic Chemistry, 44:21, 3711-3712 (1979)    German Patent No. DE 2,545,292 issued April, 1979    Suginome et al, Photoinduced Transformations. 73. Transformations of Five-(and Six-) Membered Cyclic Alcohols into Five-(and Six-) Membered Cyclic Ethers-A New Method of a Two-Step Transformation of Hydroxy Steroids into Oxasteroids, Journal of Organometallic Chemistry 49, 3753-3762, (1984)
Adamantane and substituted adamantane are the only readily available diamondoids. Diamantane and triamantane and substituted diamantanes have been studied, and only a single tetramantane has been synthesized. The remaining diamondoids were provided for the first time by the inventors Dahl and Carlson, and are described for example, in U.S. Patent Application Ser. No. 60/262,842 filed Jan. 19, 2001 and PCT US02/00505 filed 17 Jan. 2002.